Stroke incidence data has been collected for the population of a well-defined geographic area located in three counties in southern Alabama. About 160 persons hospitalized with a stroke which occurred in 1980 were identified from a population of about 100,000 persons. These data provide incidence rates by age, sex, race, and stroke type. The age adjusted incidence rate for blacks was almost twice the rate for whites. Medical history as well as other factors were collected for each stroke case. Two-thirds of the stroke cases had a history of hypertension and one in five had a history of diabetes.